Process of treating printed paper for use as paper making stock



Patented Aug. 9, 1932 UNITED STATES PATENT OFFICE LOGAN A. DILS, OF CHICAGO, ILLINOIS, ASSIGNOR TO KELLOGG-DILS, INQ, OF CHICAGO,

ILLINOIS, A CORPORATION OF DELAWARE PROCESS OF TREATING PRINTED PAPER FOR USE AS PAPER MAKING STOCK No Drawing. Application filed December2, 1930, Serial No. 499,610. Renewed December 12, 1931.

This invention relates to a process for treating-printed paper for the purpose of freeing thesame from printers ink and placing the same in condition to be used either alone or in admixture with other fibrous material for making paper such, for example, as newsprint paper.

Prior to the present invention, many efforts have been made to remove the ink from waste printed paper, to the end that the de inked paper may be used as raw material in the paper making art, either alone or mixed with other paper making fibers. Such efi'orts, however, have only been partially successful.

The ink has not been completely removed from the printed paper, and the stock made from such paper is, therefore, injuriously contaminated by the presence of the ink therein, and the same cannot be used for making a satisfactory print paper. For this reason, the practical use of such stock for commercial operations has been limited to'the use of a small percentage thereof in admixture with new stock.

25 One of the objects of the present invention is to rovide a process whereby the ink shall be su stantially all removed from the paper,

to the end that the stock thus secured may be used alone in making newsprint paper, or, If preferred, shall form the main body of the stock mixed with a small percentage of sulphite or other fiberfor making newsprint aper. A further object is to remove the ink iiom the printed paper at a minimum cost, to

a the end that the cost of the newsprint paper shall be largely decreased. A still further object is to produce from old printed paper newsprint paper of a qualitye ual to-- the original paper from which the in has been removed.

With these objects in view, printed paper, whether newspaper or other printed paper, is placed in any suitable fiber defiberizer (such for example that shown, described and claimed in my application Serial No. 456,- 270),. and the paper is therein shredded or finely; divided by passing through the defiberizer wile being sprayed with cold water.

Any other means by which the paper is finely divided may be employed.

In any suitable commercial beater used in the paper making art for beating fibers is placed a solution consisting of Per cent Water as Sodium hydroxide 10 Sodium borate 25 Trisodium phosphate 4.- Potassium carbonate 1 all by weight. 60

This solution is heated in the heater to 212 F. or more (as high as 225 at atmospheric pressure. The printpaper, shredded or. otherwise finely divided as above described, is placed in the hot solution in the heater, and the same beaten for from 5 to 7 minutes or longer, depending somewhat on the character of the ink-and paper being treated. As a result of this operation in the beater, the carbon and other ingredients of the ink rise to the surface of the solution and are removed by skimming or otherwise, after which the beaten mass is removed from the beater and washed in cold water, though warm Water may be used if desired. The beaten. washed mass thus obtained may be used either alone or mixed with sulphite or other paper making fiber for making newsprint paper. It will be found that the mass is practically free from the deleterious printers ink, and that paper made from this mass alone is equal in color, strength and other respects to newsprint paper made from new paper stock ordinarily used for makingsuch paper, and this at a cost very much less than is the case when newsprint paper is made from new stock.

What is claimed is:

1. The process of making paper-making stock from printed paper, which consists in finely shredding printed paper, then heating it at atmospheric pressure in a hot solution containing sodium hydroxide, sodium borate, trisodium phosphate and potassium carbonate, and then washing the beaten mass.

2. The process of making paper-making stock from printed paper, which consists in finely shredding printed paper in the presence of moisture, then subjecting the same to the action of a solution of sodium hydroxide,

- sodium borate, trisodium phosphate and potassium carbonate, and then washing the mass in water.

3. The process of making paper-making stock from printed paper, which consists in finely dividing printed paper, then subjectin the same to the action of a solution contaming the following ingredients in approximately the following proportions by weight, to wit water (30%, sodium hydroxide 10%, sodium horate 25%, trisodium phosphate 4%,. and potassium carbonate 1'72 and then washing the mass in water. 4. The process of making papern1aking stock from printed pa r, which consists in finely dividing printer paper, then heating the same for from 5 to 7 minutes in a solution heated to approximately 212 F.. said solution being composed of approximately 60% water, 10% sodium hydroxide. 25% sodium borate, 4% trisodium phosphatc. and 1% potassium carbonate, and then washing the. beaten mass.

5. The process of making paper-making Q stock from printed paper, which consists in finely dividing printed paper. then beating the same for approximately 6 minutes in a hot: solution of sodium hydroxide, sodium box-ate, trisodium phosphate and'potassium I) carbonate, then skimming the solution, re-

.moving the beaten mass from the solution, and then washing the said mass.

6. The process of making paper-making stock from printed paper, which consists in I: shredding or otherwise finely dividing the apr in the presence of moisture, thenbeatang the same for from 5 to 7 minutes in a solution heated to approximately 212 F., said solution being'composed of approxin mately 60% water, 10% sodium hydroxide,

25% sodium borate,-.4% trisodium phosphate, and 1%- potassium carbonate, skimming the solution, removing the mass therefrom, and then washing said mass.

5 In testimony whereof I have signed this specification.

' -LOGAN 'A. DILS. 

